# US 2021/0276693 A1 · Propeller governor for electric synchronous thrust > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0276693 A1 - Document ID: US20210276693A1 - Status: Published application - Kind: A1 - Application number: 17/184,115 - Filed: 2021-02-24 - Published: 2021-09-09 - Earliest claimed: 2020-03-03 - Assignees: Embraer S.A. - Applicants: Embraer S.A. - Inventors: Ierko de MAGALHÃES GOMES - Web page: https://patentgrep.com/patent/US20210276693A1 ## CPC - F02C 6/206: {the vehicles being airscrew driven} - B64C 11/305: {characterised by being influenced by other control systems, e.g. fuel supply} - B64C 11/40: automatic - B64C 11/44: electric - B64D 27/33: Hybrid electric aircraft - B64D 31/18: for hybrid-electric power plants - B64D 35/025: of parallel type - F01D 7/00: Rotors with blades adjustable in operation; Control thereof (for reversing F01D1/30) - F01D 17/24: electrical - B64D 2221/00: Electric power distribution systems onboard aircraft - F05D 2220/323: for aircraft propulsion, e.g. jet engines - F05D 2220/76: an electrical generator - F05D 2260/74: by turning around an axis perpendicular the rotor centre line - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - B64C: AEROPLANES; HELICOPTERS - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A thrust propeller variable pitch actuator is controlled by a governor that uses propeller pitch as a variable to increase or decrease torque—not to maintain the propeller speed or RPM but instead to maintain certain established electric current supplied to rotate the thrust propeller. ## Claims ### Claim 1 An aircraft control system for use with a variable pitch propeller rotated by an electric motor supplied by a supply current, the aircraft control system comprising: an actuator that controls the variable pitch of the propeller; and an electric circuit coupled to sense the current drawn by the electric motor and to control the pitch actuator in response to the sensed current drawn in order to vary the torque the electric motor applies to rotate the variable pitch propeller and thereby maintain the current at a set point. ### Claim 2 (depends on 1) The aircraft control system of claim 1 wherein the electric circuit includes a comparator that compares the sensed current to the set point. ### Claim 3 (depends on 2) The aircraft control system of claim 2 further including a pilot control that establishes the set point. ### Claim 4 (depends on 3) The aircraft control system of claim 3 wherein the pilot control comprises a thrust control. ### Claim 5 (depends on 1) The aircraft control system of claim 1 further including an alternator that is configured to supply the current. ### Claim 6 (depends on 5) The aircraft control system of claim 5 wherein the alternator is connected to a thermal engine such as a gas turbine engine. ### Claim 7 (depends on 6) The aircraft control system of claim 6 wherein the alternator is configured to produce a polyphase alternating current, and the propeller rotates in response to the electric motor receiving the polyphase alternating current and synchronously rotating at a frequency of the polyphase alternating current frequency. ### Claim 8 (depends on 1) The aircraft control system of claim 1 wherein the electric circuit provides hysteresis. ### Claim 9 (depends on 1) The aircraft control system of claim 1 wherein the electric circuit provides closed loop feedback. ### Claim 10 In an aircraft of the type having a variable pitch propeller coupled to an electric motor supplied by a supply current, a control method comprising: sensing the supply current; and hydraulically controlling the variable pitch of the propeller in response to the sensed supply current to maintain the sensed supply current at a set point. ### Claim 11 (depends on 10) The control method of claim 10 wherein controlling includes comparing the sensed supply current with a set point. ### Claim 12 (depends on 11) The control method of claim 11 further including manually establishing the set point. ### Claim 13 (depends on 12) The control method of claim 12 wherein manually establishing the set point comprises operating a thrust control. ### Claim 14 (depends on 10) The control method of claim 10 further including supplying the supply current with an alternator. ### Claim 15 (depends on 14) The control method of claim 14 further including rotating the alternator with a thermal engine. ### Claim 16 (depends on 15) The control method of claim 15 further including producing a polyphase alternating current with the alternator, and rotating the propeller in response to a synchronous motor supplied by the polyphase alternating current. ### Claim 17 (depends on 10) The control method of claim 10 further including providing hysteresis. ### Claim 18 (depends on 10) The control method of claim 10 further including providing closed loop feedback. ### Claim 19 An aircraft comprising: a variable pitch propeller rotated by a synchronous electric motor; a pitch actuator configured to control the variable pitch of the propeller; a current sensor connected to sense current drawn by the synchronous electric motor; and a controller operatively coupled to the current sensor and configured to control the pitch actuator in response to the sensed current drawn. ### Claim 20 (depends on 19) The aircraft of claim 19 wherein the controller comprises a comparator that compares the sensed current drawn to a predetermined set point.